Uniform shuttle tension



' Nov. 30, 1943. R. E. CHARD 2,335,483

UNIFORM SHUTTLE TENSION Filed Sept. '7, i942 INVENTOR. E/cHA/ea E CHAED.

BY Q gi ATTo ENE Y.

Patented Nov. 30, 1943 UNIFORM SHUTTLE TENSION Richard E. Chard,Milford, Mass, assignor to Draper Corporation, Hopedale, Mass, acorporation of Maine Application September 7, 1942 Serial No. 457,570

'12 Claims.

. This invention relates to threading blocks for loom shuttles, and moreparticularly to a means for automatically controlling the tension on thethe filling thread issuing from the shuttle.

In a fly shuttle loom where the filling is withdrawn from a carriersecured in the shuttle, one of the problems encountered in producing auniform weave in the cloth is that of keeping the filling thread underan unvarying tension during the whole weaving operation.

It is common practice in the art to provide, in a threading block, atension pad which resiliently will engage the running filling thread andcreate a frictional resistance on it to produce tension therein. In suchprior devices, however, the pad was made to engage the filling threadconstantly with a predetermined pressure, and no means were providedautomatically to change the amount of the friction created by the pad tocompensate for changes in the tension of the filling thread resultingfrom other forces imposed thereon.

It is an object of my invention to provide for a shuttle a threadingblock having a means therein frictionally to engage a filling thread ina manner to produce tension in it as it is being withdrawn from the sidedelivery eye, and to provide another means separate from but cooperatingwith the friction means and actuated by contact with the filling threadat a point spaced apart from the friction means to govern the operationof the latter means so that the tension producing effect of it will beregulated in accordance with the requirements arising from the workingconditions of the filling.

It is another object of my invention to provide a threading block havinga tension pad resiliently pressing upon the filling thread, a meansseparate from but cooperating with the tension pad, and actuated by thetension in the filling thread to control the action of the tension padin a manner to cause the pressure thereof to be varied in accordancewith changes in tension in the filling thread to compensate forvariations in the tension arising from other sources and thereby keepthe resultant tension in the filling thread substantially uniform.

It is a further object of my invention to provide a threading block, ofthe type described above, in which the tension pad will operate as athread trap under the influence of the controlling de vice.

These and other objects may be attained by the construction which I haveshown as an exemplary modification of my invention in the accompanyingdrawing, although it will be understood that I do not wish to be limitedto the specific details of the form of my invention, illus-.- tratedtherein.

In the drawing:

Fig. 1 represents a partial plan view of a shut-, tie with a fillingcarrier therein, and shows the disposition in the shuttle of a threadingblockembodying my invention;

Fig. 2 represents an elevational view of a section of the threadingblock, taken approximately on the line 2-2 of Fig. 1; v

Fig. 3 represents an elevational view ofv an end of the threading block,looking toward the filling carrier, and shows the position assumed by afill-, ing thread in it when not under tension;

Fig. 4 represents a sectional plan view of the threading block takenapproximately on the line- 4-4 of Fig. 6, and shows the position assumedFig. 5 represents the same sectional plan view 7 of the threading blockas shown in Fig. 4, and shows the position assumed by the parts when thefilling thread is under comparatively high tension;

Fig. 6 represents an elevational view of anend of the threading blocklooking away from the filling carrier and toward the point of theshuttle; Fig. 7 represents a sectional view in elevation of thethreading block, taken on the line 1--1 of ig. 1; I Fig. 8 represents aplan view of the bottom sur-' faces of the threading block.

Referring to the drawing, the shuttle [has a filling carrier 2 attachedwithin it, from which the filling F is unwound and led through thethreading block 3 which directs it to the side delivery eye 4 fromwhence it is continuously drawn to be woven into a fabric. Thisarrangementis well known in the art and therefore an-extended:description of it is not thought to be necessary: here.

The threading block may be made ofmetal, or other suitable material, andis constructed so; that it may be inserted in a recess in the body. ofthe shuttle and secured therein in a; manner; well known in the art.

Within the threading block is formed a longito, and is in communicationwith, the top' surface 8 of the threading block. The threading block isplaced in the shuttle so that the longitudinal passage is in alignmentwith the filling carrier, and the top surface is so shaped that a threaddrawn from the filling carrier and along the top surface will be leddown into the thread passage.

A projection 9 is formed on the threading block, extending downwardlyfrom the top thereof, and is placed outwardly of the end of the threadpassage in a position to engage a filling thread running through thepassage and lead it transversely of the shuttle into the space Ill andout of the side delivery eye 4. A post ll may be placed on the threadingblock adjacent the side delivery eye to form a bearing surface for therunning filling thread.

During normal operation the filling thread will contact surfaces of thethreading block and thereby encounter frictional resistance to itstravel. The drag produced will result in the thread being drawn from theside delivery eye under tension.

A certain amount of tension in the filling thread is essential if it isto be laid properly in the shed. However, with some types of fillingthread and under some operating conditions the tension produced by suchmeans has not been found adequate. In such cases in order to assure thatthe filling thread will operate under proper tension, it has beenproposed to place a device in the threading block to engage the fillingthread and increase the tension thereon. Such a device may have variousforms, one of which is shown in the drawing.

As illustrated, the friction device may coinprise an element l2, knownas a tension pad, positioned to engage the filling thread in its travelthrough the threading block, and, under the influence of a spring l3,force it into more intimatecontact with a surface of the thread passage,thereby increasing the friction on it.

In the device illustrated, the tension pad has an inverted L shapedformation, one end portion M of which is loosely inserted into anopening l5'formed in the wall of the threading block. The other endportion of the tension pad has an opening l6 formed in it, and throughthis opening is placed a pin I1, the ends of which are secured in thebody of the block. In this manner, the tension pad is constrained frommoving out of its set position longitudinally of the threading block,but is free to move laterally of the thread passage.

'An opening I8 is placed in the wall 8 in approximate alignment with thecenter point of the tension pad, and is screw threaded to receive a setscrew 19. The spring 13 is inserted through the opening it intoengagement with the back of the tension pad [2, and the set screw'lB isthreaded into the opening to abut the spring and cause it to press thetension pad against the wall I of the thread passage.

The top portion of the tension pad is rounded, as at 20 to form an entryfor the thread as it is being led into the thread passage 5.

It will be seen from this construction that as the filling thread entersthe thread passage from the top of the threading block, it will assume'a position between the tension pad and the side wall 7 of the threadpassage, and during subsequent operations the tension pad will afiectthe amount of friction imposed on the thread.

".In'suc'h a device the pressure of the tension pad on the thread can beregulated by removing the shuttle from the loom andmanipulating the setscrew l9. However, the adjustment cannot be made while the shuttle is inoperation. The tension pad, therefore, will generate a fixed amount oftension in the filling thread at its point of pressure applicationregardless of the amount of tension occurring therein due to theconditions under which the filling thread is operating at the time.

It is well known that the tension in the filling thread variesconsiderably over a wide range during normal loo-1n operations, and myinvention contemplates the use of a means to regulate the tensionresulting from the friction devices that it will be effective only tothe amount needed at a particular instant.

It might be well to note some of the circumstances affecting the tensionin the filling thread during the Weaving operation,

It is usual practice detachably to secure the filling carrier within arecess in the shuttle body and to dispose it longitudinally of theshuttle so that the tip of the carrier is adjacent the threading blockand the base is grasped by a holding means.

As the filling is unwound from the carrier, that part of it adjacent thetip is withdrawn first, and subsequently other portions farther from thetip, so that the filling is unwound from the carrier progressively fromthe tip to the base portions thereof.

By this construction, as the filling is withdrawn from the carrier it isunwound circumferentially around it and passes along the body of thecarrier in a longitudinal direction until it is released at the free tipportion, from whence it runs through the threading block.

The filling thus comes in contact with increasingly greater lengths ofthe exposed portion of he body of the filling carrier, and thefrictional resistance on the filling thread due to this contactcontinuously increases. As a result the'tension of the filling beingwoven into the cloth is constantly changing. Because of this, imperfectcloth is sometimes produced. I

Another factor afiecting the tension of the filling thread occurs whenthe shuttle is checked at the end of its travel through the shed. Oncoming into the shuttle box the shuttle is checked very'abruptly, andthe inertia of the filling thread tends to cause an excessive amount offilling to be unwound after the shuttle is stopped. Unless means areprovided to prevent it, the filling thread will continue to be drawnthrough the threading block to relieve any tension on the thread, andthe filling will be in a slack condition when it is beaten into thefell, resulting in imperfect cloth.

If a tension pad is placed in the thread passage, as shown in thedrawing, it will impose sufiicient resistance on the filling to cause itto remain under tension after the shuttle is checked, even though anover supply of filling has been unwound from the filling carrier duringthe checking operation.

in the carrier receiving recess of the shuttle from whence it will bedrawn on subsequent loom operation.

In order to control the amount of friction placed on the filling threadto compensate for changes in tension arising therein, I have provided ameans which will be actuated by the tension in the filling to affect thepressure produced by the tension pad.

This means may comprise a lever member 2| The action of the tension padwill cause the excess filling to be retained I placed in a channel 22formed in the bottom surface of the threading block, and extendinglongitudinally thereof in a plane parallel to the central plane of thethread passage 5. The lever member is loosely secured in the channel sothat it may have a rotary motion therein.

The end of the lever nearest the tension padv is bent upwardly in ahook-like formation which is made to embrace loosely the pin I! to whichthe tension pad is affixed. This hook-like end bears against the tensionpad on the same side as that contacting the wall 1 of the threadpassage. A recess 24 is formed in the body of the threading block topermit the end 23 of the lever to be inserted in this position.

Th other end of the member 2| is bent upwardly at an angle which willcause it to extend transversely of the end of the thread passage 5, asat 25, and is further bent as at to place the terminus 21 of the levermember in a cavity 28 formed in the under part of the top surface 8 ofthe threading block. The end 2'! of the lever is thus mounted in thethreading block in such a position that a thread entering the threadpassage from the top surface 8 will engage the portions 26 and 25 of thelever and remain in contact with it as it is guided out of the sidedelivery eye.

The proportions of the lever member 2| are such that the bent portion 25lies opposite the space ill.

The lever member is placed in a position in relation to the cavity 28,the channel 22 and the recess 26 with such clearance that it may berotated slightly to cause the end portions 23 and 25 to movetransversely of the thread passage 5.

A member 29 is aiilxed to the bottom of the threading block to retainthe lever member 2| in operative position. The member 29 may be held inposition by an ear 30 contacting a face of the shuttle block, as at 3!,and an upturned portion 32 contacting another face of the threadingblock as at 33, the dimensions of the parts being such that theresiliency of the material from which th member 29 is made will causethe parts 3!! and 32 to contact the faces of the shuttle block withsufiicient force to hold the parts together until the threading block issecurely fastened in the shuttle.

The upturned portion 32 of the member 253 may be extended upwardly alongthe adjacent face of the threading block to a point near the top surfacethereof, and it may have formed in it an opening 34 in alignment withthe center of the thread passage 5. The opening 34 has at the top anarrow thread passage 35 in a position to cause a filling thread beingled into the threading block to enter into it.

In this manner there is provided a thread trap which will prevent thefilling thread from swirling out of th threading block as it is unwoundfrom the filling carrier.

A notch 36 placed in the end of the thread passage wall 7 adjacent thetension pad forms a means whch enables uneven portions, such as knots,in the filling thread to enter between the tension pad and the side wallof the thread passage without catching on the parts and causing thethread to break. The notch also aids the filling thread to maintain acentral running position.

Under working conditions, a filling thread will pass from the fillingcarrier, through the opening 34, between the tension pad I? and the wall1, along the thread passage 5, around the portion 25 of the lever member2|, through the sion.

space H] and thence through the side delivery eye of the shuttle.

When there is no tension in the filling thread, the tension pad willexert its full spring pressure thereon as shown in Fig. 3. However, asthe tension in the thread increases, the thread will act on the endportion 25 of the lever member 2| to rotate it in the direction of theside delivery eye. This will cause the end portion 23 of the levermember 2| to be rotated in the same direction.

Since the end portion 23 bears against the tension pad, and since it isrestrained by the channel 22 from moving transversely of the threadpassage, the result of the rotation will be to cause the bottom of thetension pad to be forced away from the wall 1, and thereby exert lesspressure on the filling thread. When the bottom of the pad is moved inthis direction, th spring l3 will act as a fulcrum about which the padwill pivot to cause the top portion thereof to remain in contact withthe wall 1. Therefore, although the pad is forced entirely out ofcontact with the filling thread, the position of the pad will cause thethread to remain in the space between the pad and the wall of the threadpassage.

When the pressure exerted by the tension pad is reduced, the tension inthe filling thread will be decreased. The force on the lever member 2|will be diminished until it will not be sufficient to cause furtherrotation of the parts, and they will reach a state of equilibrium inwhich the filling thread is being withdrawn at the proper ten- If thetension of the filling thread becomes excessive, the part 25 of thelever member 2| will be rotated an amount suiiicient to cause the tension pad to be displaced far enough from the wall I so it will no longercontact the filling thread, and hence will be entirely ineffective tocreate additional tension. This condition is shown in Fig. 5.

It will be seen, therefore, that the pressure of the tension pad isautomatically controlled to compensate for tension arising in thefilling thread from other sources. The control is positive andinstantaneous.

When the tension on the filling thread is sud-- denly relaxed, the levermember 25 will be no longer effective to control the action of thetension pad and the full pressure thereof will be exerted on the thread.This condition occurs when the shuttle is checked in the shuttle box.Therefore, at this time, the full pressure of the tension pad is madeavailable to hold the filling thread at the proper tension while it isbeing beaten into the fell.

Having thus described a preferred embodiment of my invention, I claim:

1. In a shuttle for an automatic filling replenishing loom, a threadingblock having a thread passage therein, a friction means in saidthreading block and positioned frictionally to engage a filling threadpassing through said block, and

a second means separate from but cooperating with said friction meansand constructed and arranged to be actuated by said filling thread tocause said friction means to be effective to vary the friction on saidfilling thread in inverse relationship to the tension in said thread.

2. In a shuttle for an automatic filling replenishing loom, a threadingblock having a longitudinal thread passage therein, a tension pad placedin said thread passage and positioned to press a filling thread betweensaid tension pad and a wall of said passage, and means separate frombutcooperating with said tension pad and actuated by said filling thread tocause .the pres sure of said tension pad on said filling thread to beeffective in inverse relationship to the tension therein.

3. In a shuttle for an automatic filling replenishing loom, a threadingblock having a longitudinal thread passage therein, a tension pad placedin said thread passage and positioned to press a filling thread betweensaid tension pad and a wall of said passage, and means separate from butcooperating with said tension pad and actuated by said filling thread tocause the pressure of said tension pad on said thread to decrease as thetension therein increases.

4. In a threading block for a loom shuttle, a longitudinal threadpassage, a spring pressed tension pad placed in said passage andpositioned to press a'filling thread between said tension pad and a wallof said passage, and means in said threading block separate from said.tension pad but in engagement therewith and with the filling thread, andcooperating with said filling thread and said tension pad to cause thepressure of said tension pad to be effective in inverse relationship tothe tension in said filling thread.

5. In a threading block for a loom shuttle, a thread passage, a frictionmeans positioned in said passage to. engage a filling thread, and meansin said threading block separate from said friction means andcooperating with said friction means and said filling thread to causesaid friction means to be effective to create friction on said fillingthread in inverse relationship to the tension therein.

6. In a threading block for a loom shuttle, a longitudinal threadpassage, a spring pressed tension pad placed in said passage andpositioned to press a filling thread between said tension pad and a wallof said passage, and means in said threading block separate from saidtension pad but in engagement therewith and with the filling thread, andcooperating with said filling thread and said tension pad to cause saidtension pad to reduce pressure on said filling thread as the tensiontherein increases.

7. In a threading block for a loom shuttle, a longitudinal threadpassage, 2. spring pressed tension pad placed transversely of saidpassage and positioned to press a filling thread between said pad and aside wall of said passage, a lever member operably mounted in saidthreading block and having a portion positioned to engag the fillingthread and another portion positioned to engage the tension pad, saidlever member being mounted so that the said portions are capable ofmovement transversely of the thread passage, said lever member beingseparate from said tension pad and being constructed and arranged to beactuated by the filling thread to cause the tension pad to engage thefill ng thread with a pressure inversely proportional to the tension insaid thread.

8. In a threading block for a loom shuttle, a longitudinal threadpassage, a resiliently mounted tension pad positioned to movetransversely of said thread passage to press a fil ing thread betweensaid pad and a side wall of sa d passage. a lever member operablymounted in said threading block and having a portion positioned toengage the filling thread and another portion positioned to engage thetension pad, said lever memher being mounted so that the said portionsare capable of movement transversely of the thread passage, said levermember being separate from said tension pad and being constructed andarranged so that it will cooperate with the filling thread and thetension pad to cause the portion of the lever member engaging the saidpad to force the said pad to decrease pressure on the filling threadwhen the other portion of the lever member is moved transversely of thethread passage by the filling thread unde tension.

9. In a threading block for a m shuttle, a longitudinal thread passage,a tension pad resiliently mounted for movement transversely of saidpassage and into engagement with a side wall thereof and positioned toengage a filling thread between said pad and the said wall, and means inthe threading block cooperating with the filling thread and the tensionpad and constructed and arranged to be actuated by the filling threadunder tension to force the bottom portion of the tension pad out ofengagement with the said side wall while the top portion of said padremains in contact therewith.

10. In a threading block for a loom shuttle, a longitudinal threadpassage, a spring pressed tension pad positioned to move transversely ofsaid passage to press a filling thread between said pad and a side wallof said passage, a lever member operably mounted in said threading blockand having a portion in contact with the lower part of the tension padand another portion positioned to engage the filling thread at a pointspaced apart from said tension pad, said lever member being mounted sosaid portions are capable of movement transversely of the thread passageand being constructed and arranged to be actuated by the filling threadto force the lower portion of said tension pad away from said side wallagainst the spring pressure to cause said tension pad to relieve thepressure on the filling thread.

11. In a loom shuttle, a longitudinal recess containing a fillingcarrier, a threading block placed at one end of the shuttle and having alongitudinal thread passage in substantial alignment with and incommunication with said recess, a friction means positioned at the endof said longitudinal thread passage adjacent said recess, said frictionmeans comprising a spring pressed tension pad movable transversely ofthe thread passage and positioned resiliently to engage a filling threadbetween said pad and a side wall of said thread passage, a lever memberplaced in said threading block longitudinally of said thread passage andhaving one end portion thereof bent at substantially a right angl andpositioned transversely of the said thread passage adjacent the endopposite to that containing the friction means and the other end portionof said lever member having a hook-like formation, said hook-likeportion being positioned to lie flat against said tension pad on thethread engaging side thereof, said lever being mounted in the threadingblock in a manner to permit the said end portions thereof to be movedpivotally transversely of the thread passage, said lever being soconstructed and arranged that the said. right angled end portion thereofwill be moved pivotally transversely of the said thread passage underthe action of tension in a filling thread passing through said threadingblock and thereby cause the said hook-like end portion to be moved pivotally transversely of the thread passage in a manner to engage the saidtension pad and cause it to move away from the filling thread engagedbetween the said tension pad and the said side Wall of the threadpassage to thereby reduce the frictional effect of the tension pad onthe filling thread.

12. In a shuttle for an automatic filling replenishing loom, saidshuttle having a hollow longitudinal portion for accommodating a fillingcarrier, and a side delivery eye, a threading block having alongitudinal thread passage therein communicating with the top surfaceof said threading block, said surface being formed to guide a fillingthread into said thread passage, a friction means placed at one end ofsaid threading block in a position to engage a filling thread as itenters the said thread passage, said friction means comprising a tensionpad mounted on one vertical side wall of said thread passage and springpressed into engagement with the other vertical side Wall thereof, saidtension pad being formed at the top portion thereof to provide means fora filling thread to be inserted from the top surface of said threadingblock to a position between the said tension pad and the said side wallengaging it, said tension pad being constructed and arranged so the topportion of said pad will contact the said side wall of the threadpassage when the filling thread is in the aforesaid position to therebyform a trap for the filling thread, a lever member mounted in a channelin the bottom of the threading block and longitudinally thereof, saidlever member having an upturned portion at one end engaging the bottompart of said tension pad and an upturned portion at the other endextending upwardly from the bottom of said threading block andtransversely of said thread passage terminating in a recess in the underside of said top surface said last named upturned portion of the levermember being positioned to engage a filling thread led into said threadpassage from said top surface of the threading block and at a pointbetween the thread passage and the said side delivery eye of theshuttle, said lever member being mounted in the threading block in a manner to permit said upturned end portions to be moved pivotallytransversely of said thread passage, said lever member being constructedand arranged to cause the thread engaging upturned portion thereof to bemoved pivotally transversely of the thread passage under the action oftension in the filling thread and to thereby cause the other upturnedend portion of the lever member to contact the bottom part of thetension pad and force it against the spring pressure occurring on it toreduce the pressure imposed on the filling thread placed between thetension pad and the vertical side wall of the thread passage.

RICHARD E. CH-ARD.

